The rotating cast of characters that will make up the main card of “Strikeforce: Carano vs. Cyborg” has taken another hit, and a welterweight title matchup has today gone up in smoke.

After failing to appear for a pre-fight drug screen on Friday, and again today, Nick Diaz will not be licensed by the California State Athletic Commission for the Aug. 15 event at HP Pavilion in San Jose, Calif.

As MMAjunkie.com previously reported, Strikeforce was holding out hope that Diaz would still be approved for the bout, but the welterweight missed today’s re-scheduled “second chance” deadline set by the CSAC. Forced to take action, Strikeforce called on Taylor to fight on just five days’ notice.

Infamous for his removal from “TUF 7″ after qualifying for the season’s finals, Taylor then lost by submission to C.B. Dollaway at UFC Fight Night 14 in July 2008. Taylor has since gone on to record seven-straight wins, including two victories in July. In fact, the bout will be Taylor’s third in just five weeks.

While Diaz and Hieron were scheduled to meet for Strikeforce’s vacant welterweight title, Coker confirmed the rescheduled matchup will be a non-title affair.

Coker also told MMAjunkie.com he is currently lobbying Showtime for permission to not only keep the Hieron vs. Taylor matchup on the evening’s televised card, but to also promote a heavyweight contest between Mike Kyle and Fabricio Werdum to the Showtime-broadcast portion of the evening.

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